Keep trying. Yes, you do have to use the header and or footer for this.

"Some sort of watermark" That is what something in a header or footer looks like when you are in Print View. It prints (or goes to pdf) as full strength.

Go into your template.
Note "template," not "document." This is Word jargon and important.
Templates in Microsoft Word

1. Insert > Header > Edit Header (down at the bottom of choices).
2. Ctrl+X to cut all.
3. Check the box for Different First Page.
4. You are now in the "first-page" header.
5. Paste. Delete the last paragraph mark.

Save your template.